The present invention relates to a hand truck for carrying boxes, parcels, furniture and other heavy items.
A conventional hand truck comprises an elongate upright chassis having a handle at the upper end and having a load lifting platform (toe plate or fork) at the opposite, lower end. The platform extends outward from the bottom of the chassis at an angle of approximately 90.degree..
The chassis and platform are carried by a pair of rugged wheels, one on each side of the lower end of the chassis. The wheels are rotatable about individual axles on opposite sides of the chassis or about a single, common axle which extends across the width of the chassis. In either case, the wheels rotate about a common wheel axis which extends transversely to the longitudinal axis of the chassis.
A hand truck of this type is extremely useful, but it suffers from the drawback that it is inherently unstable. When carrying heavy loads (e.g., 200-700 pound loads) the hand truck has a tendency to either tip forward to its upright position, to where the load-bearing surface of the platform is horizontal, or tip backward to where the longitudinal axis of the chassis is essentially horizontal. With such heavy loads, a hand truck operator must be careful to maintain the hand truck in a balanced position with both the longitudinal axis of the chassis and the plane of the platform at an angle of about 45.degree. with respect to the vertical (and horizontal).